title: Improved air quality and attenuated lung function decline: modification by obesity in the SAPALDIA cohort.
abstract: BACKGROUND
  Air pollution and obesity are hypothesized to contribute to accelerated decline in lung function with age through their inflammatory properties.
  
  
  OBJECTIVE
  We investigated whether the previously reported association between improved air quality and lung health in the population-based SAPALDIA cohort is modified by obesity.
  
  
  METHODS
  We used adjusted mixed-model analyses to estimate the association of average body mass index (BMI) and changes in particulate matter with aerodynamic diameter ≤ 10 µm (PM10; ΔPM10) with lung function decline over a 10-year follow-up period.
  
  
  RESULTS
  Lung function data and complete information were available for 4,664 participants. Age-related declines in lung function among participants with high average BMI were more rapid for FVC (forced vital capacity), but slower for FEV1/FVC (forced expiratory volume in 1 sec/FVC) and FEF25-75 (forced expiratory flow at 25-75%) than declines among those with low or normal average BMI. Improved air quality was associated with attenuated reductions in FEV1/FVC, FEF25-75, and FEF25-75/FVC over time among low- and normal-BMI participants, but not overweight or obese participants. The attenuation was most pronounced for ΔFEF25-75/FVC (30% and 22% attenuation in association with a 10-μg/m3 decrease in PM10 among low- and normal-weight participants, respectively.)
  
  
  CONCLUSIONS
  Our results point to the importance of considering health effects of air pollution exposure and obesity in parallel. Further research must address the mechanisms underlying the observed interaction.
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland. tamara.schikowski@unibas.ch
authors.forename: Tamara
authors.initials: T
authors.lastname: Schikowski
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Schaffner
authors.forename: Flurina
authors.initials: F
authors.lastname: Meier
authors.forename: Harish C
authors.initials: HC
authors.lastname: Phuleria
authors.forename: Andrea
authors.initials: A
authors.lastname: Vierkötter
authors.forename: Christian
authors.initials: C
authors.lastname: Schindler
authors.forename: Susi
authors.initials: S
authors.lastname: Kriemler
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Zemp
authors.forename: Ursula
authors.initials: U
authors.lastname: Krämer
authors.forename: Pierre-Olivier
authors.initials: PO
authors.lastname: Bridevaux
authors.forename: Thierry
authors.initials: T
authors.lastname: Rochat
authors.forename: Joel
authors.initials: J
authors.lastname: Schwartz
authors.forename: Nino
authors.initials: N
authors.lastname: Künzli
authors.forename: Nicole
authors.initials: N
authors.lastname: Probst-Hensch
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000393:Air Pollutants / Q000032:analysis* / Q000633:toxicity*; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000453:epidemiology*; D010316:Particle Size; D012123:Pulmonary Ventilation / Q000187:drug effects*; D012131:Respiratory Insufficiency / Q000139:chemically induced / Q000150:complications / Q000453:epidemiology*; D013557:Switzerland / Q000453:epidemiology
chemical_list: D000393:Air Pollutants